The processes of cultural heritage sites' degradation reveal interactions between the chemical characteristics of the substrates, the underlying substrate penetration, and the microbiota systems. Microorganisms penetrate the stone, causing extensive disaggregation of the materials. This chapter reveals comparative studies between the usual research approaches applied in biodegradation studies, especially optical microscopy, epifluorescence, and electron microscopy (SEM). These in situ microscopy techniques propose some complex analyses for the evaluation of the relationship between the microorganism's cells and the stone surfaces (adherence, interactions), and also for the evaluation of the level of health or balance of the niche complex, from mesoscale to microscale. The stages of the exact monitorization and evaluation of lithotypes and deterioration phenomena are periodical sampling and monument mapping. The aim of this chapter is to identify microscopical methods used in biodegradation studies, especially the facilities provided by these methods. Our in situ analysis (light microscopy, epifluorescence, and scanning electron microscopy) performed for the first time on the painted Matia-Fresco Loggia (Corvin Castle, Romania) highlighted several aspects, such as mixtures of mineral elements with different chromatic appearance and porosity, shredding degradation, depigmented areas, cracked portions, and highly biota activity (bacterial and fungal) on painted surface.

The works of art analyzed in this research study are part of the Ovidius University Gallery collection that ensures the permanent visibility of the research results consisting in the experimental synergistic method as well as the innovative materials intended for restoration and conservation. We are sure that after the scientific investigation, the authentication and restoration of these works of art will increase their value. The synergistic methodology, to which we refer, can be defined as a sum of methods and procedures in the trans-and interdisciplinary field, which introduces the notion of "health" in the field of restoration artworks, changing the paradigm of approach as a whole, analyzing pigments, supports and all the specific painting materials. Nondestructive analytical procedures will be implemented to develop and optimize the conditions for identifying the individual types of biological impact present in works of art and of case studies on real samples. In the research activity, we used the different techniques to investigate and characterize traditional organic binders used in works of art, to see the effect on the consolidation and durability of materials, to test their functionality and usefulness while validating a viable laboratory model in relation to the natural system.

The constituent elements of the Roman Mosaic from Constanta are damaged under the activities of microorganisms present both on surfaces and in the airborne microbes. The predominance of microorganisms on the different surfaces of the edifice has led to multiple damage such as discoloration, pigmentation, wall degradation and exposed ceramic objects. Through this study we aimed to invest the diversity of microorganisms on the various substrates and levels as well as microclimate conditions. From the samples collected there were isolated and identified microorganisms, many of them with pathogenicity risks for staff and visitors. Thus, for the improvement of the surrounding conditions of the Roman Mosaic exhibition room, the need for management is aimed at reducing the microbial contaminations, based on understanding the changing conditions in the microclimate and decreasing the damage biofilm. Our study can be seen in a broader procedural in the current COVID-19 pandemic conditions.